When servicing equipment at a user location, knowledge of topology at the user location is essential to accurate troubleshooting. Furthermore, there may be no knowledge of a user's in-home wiring before additional services or equipment are offered.
Installers, technicians, and care agents are subject to guessing and frustrating trial-error evaluation of wiring. This sometimes results in unusually high installation and troubleshooting times due to unanticipated wiring challenges within the home.